Songdo, a $35 billion city-within-a-city near Seoul’s international airport that is one of the world’s largest commercial developments, turns a corner Friday with the official opening of its first phase, including a giant park, hotel, apartments and convention center.

The $35 billion planned city of Songdo in Incheon, South Korea, is slowly coming to life. In January, Posco Engineering turned on the lights at its new “The Sharp First World” apartment complex. The overall project started in 2002 and isn’t expected to finish until the middle of the next decade. By then, about 65,000 people are expected to live in Songdo, a 1,500-acre district of Incheon, a port city about 30 miles west of Seoul.

But with 40% of the work either done or under way, Songdo’s South Korean and American developers say they believe it has reached critical mass and its completion is ensured after several years of bureaucratic tangles. In recent weeks, the number of construction workers on site has ranged from 15,000 and 20,000 as they make progress on 100 buildings. Read more on WSJ.